Nuclear Materials Science

The institute for Nuclear Materials Science NMS carries out research on the structural and functional materials that are part of present and future nuclear systems. Together with the functional design that determines the working conditions, the materials choice for the different components is the cornerstone for the realisation of safe and durable reactor systems.

Applications

The institute deals with applications that are connected to

• Power generation reactors
• Research installations
• Materials for medical imaging and therapy
• Industrial semiconductor production

The research on reactor applications focuses on the materials used in a nuclear reactor core. Broadly speaking, these materials can be divided into two big classes:

• The metallic structural materials (that assure the cooling and the enclosure of the core)
• The ceramic or metallic nuclear fuels (that produce the energy of the reactor)

The radioisotopes and semiconductors are produced in test reactors and offer unique possibilities to the medical and electronic sector. Their production requires specialised laboratories in order to deliver the materials in a safe and highly qualitative way.

Current tendencies

Inside the fission reactor core, the fission process and its resulting fission products and the neutron field constitute the typical nuclear working environment. This causes a changing chemical composition of the nuclear fuel and radiation damage in both the nuclear fuel (because of fission fragments and neutrons) and the structure materials (because of the highly energetic neutrons).

This radiation damage can have severe consequences for the behaviour of the materials.

• Structure materials can become more brittle by irradiation, causing the safety margin with regard to structure breaking during the life span to diminish.
• Long exposure to radiation and/or the environment of the reactor coolant can also bring about stress corrosion, resulting in leaking or cracking components.
• Fuels will undergo a change in physical and chemical properties, as the delivered amount of energy rises. This will alter the capacity of the fuel to remove the heat produced by nuclear fission, while the risk at a release of radioactive fission products from the fuel can increase. Here too, it is of great importance to know the remaining safety margin and to make a well-founded optimisation of the fuel use without endangering the safety.

The current tendencies in the nuclear world go to an extended use of existing installations and materials, whereas new, advanced nuclear systems are being designed that make better use of the available fuel reserves, produce less waste and reach a higher efficiency. More in particular, this means that an evolution will take place towards a higher application temperature, more intense irradiation (as regards dose and energy) and more aggressive coolants (liquid metals or gases at high temperature). Given the equal load of materials in fusion systems, the competencies developed within fission can also be applied to the materials used in fusion reactors.

NMS research strategy

These tendencies increase the request for new experimental data, advanced applications of existing knowledge and models that allow a reliable extrapolation of the acquired knowledge from laboratory to reactor conditions (both for existing, ageing reactors and new reactor concepts, for which the conditions differ from what's currently achievable in the research installations). In order to meet these challenges, the NMS institute has developed a research strategy based on a synergy between three aspects of materials research:

• Experimental research on the behaviour of materials in reactor relevant conditions in order to generate reliable data for industrial and scientific purposes.
• Fundamental materials research in order to comprehend a mechanistic and physical explanation for the observed tendencies in material behaviour.
• Description of the gained insights in mathematical models that are validated with the obtained data and allow a reliable extrapolation of the results.

This combination of experimental and theoretical research aims at assuring the own expertise and, at the same time, being able to offer services with high added value to the industry.

Institute Manager: Sannen Leo
Deputy Institute Manager: Scibetta Marc

Leaflet NMS (548 kB)

More detailed information about the institute NMS and its expert groups and research can be found in the section 'Our Research - Nuclear Materials Science'.